The present invention pertains to a jack stand for use with attachments of heavy type connectable to wheeled-type powered agricultural machines, such as a combine, for use in harvesting operations and the like. Many such types of agricultural attachments are exchangeable with the powered machine for use with different crops or different harvesting procedures, whereby it is highly convenient to have the attachment at the desired vertical position to be reconnected to the powered machine when use thereof is desired. Many types of equipment of this nature are very heavy. Also, rarely are such attachments of the same general shape although the part to be attached to the powered machine should be at the same vertical position above the ground or floor surface of a shed or building to render the attachment readily reconnectable to the powered machine when an exchange of attachments is to be made without requiring jacks or hoists.
Many types of jack stands have been developed heretofore for agricultural equipment and otherwise and the prior U.S. Patents, as listed below, represent a somewhat overall view of different types of drawbars capable of providing adjustable vertical support for tongues or drawbars of agricultural equipment:
U.S. Pat. No. 2,225,157, Court, Dec. 17, 1940 PA1 U.S. Pat. No. 2,580,545, Hill, Jan. 1, 1952 PA1 U.S. Pat. No. 2,672,318, Lee, Mar. 16, 1954 PA1 U.S. Pat. No. 2,836,432, Delp et al, May 27, 1958 PA1 U.S. Pat. No. 2,970,810, Zich et al, Feb. 7, 1961 PA1 U.S. Pat. No. 3,181,891, Moats, May 4, 1965
It will be seen from the foregoing patents that, in general, pivoted leg arrangements have been employed heretofore to provide vertical adjustment for the outer ends of tongues or drawbars relative to the ground and, in addition, the use of a pair of longitudinally movable leg members also is old, even to the extent of employing a row of holes in one member and at least one hole in the other member to receive a securing pin between aligned holes therein when a desired longitudinal adjustment of the telescoping members has been arranged.
In view of the fact, however, that many types of attachments for modern agricultural equipment have shapes and body surfaces which normally are at different distances above the ground in stored, disconnected condition, and further in view of the fact that the maximum support distance is more than twice as great as the minimum support distance, coupled with the necessity that the jack stand must be compact enough to be stored during operation of the attachment without interference with the operative parts of the attachment, attaching a jack stand thereto to maintain the connecting parts of the attachment at the level required for reconnection to the powered machine presents problems. The prior art has not developed a suitable adjustable jack stand capable of being attached to a range of different attachments to support the attachments at the desired level when stored or parked in inoperative condition and still be compactly stored during operation of the attachment.